Red-violet sulfur dye and process of making same.



UNITED STATES PATENT OFFICE.

THEODOR MUOHALL, OF BIEBRIOH, GERMANY, ASSIGNOR TO THE FIRM OF KALLE ANDCOMPANY, OF BIEBRIOH, GERMANY.

RED-VIOLET SULFUR DYE AND PROCESS OF MAKING SAME.

Specification of Letters Patent.

Patented Aug. 8, 1905.

Application filed September '7, 1904:- Serial No. 223,613.

To all whom, it may concern:

Be it known that I, THEODOR MUCHALL, a subject to the King of Prussia,Emperor of Germany, residing at Biebrich, Germany,

have invented certain new and useful Improvements in the Manufacture ofRed-Violet Sulfur Dyes, of which the following is a specification.

My invention relates to a new sulfur color dyeing a red violet oncotton. I have discovered that a poly-oxyrosindulin is formed if anaqueous suspension of benzene-azo-alphanaphthylamin is boiledwith'para-amidophenol at a reflux cooler; This rosindulin derivative hasonly very little aifinity to the cotton fiber; but it yields when meltedwith an alkali polysulfid a sulfur color which dyes on cotton ared-violet shade of considerable fastness.

In order to show the manner in. which my invention may be carried out, Igive the fol lowing example; but my invention is not limited to theparticulars of this example:

Thirty kilos benzene azo alpha-naphthylamin, thirty five kilos paraamidophenol, twenty-four kilos concentrated hydrochloric acid, and onehundred and fifty liters of water are boiled in an enameled pan fittedwith a reflux cooler until a test is completely soluble in dilutecaustic-soda lyethat is to say, until all thebenzene-azo-alpha-naphthylamin employed has entered into the reaction.This requires about five to six hours boiling. The reaction mass is nowmade alkaline with caustic-soda lye and freed from anilin formed duringthe reaction by a current of steam. The

new rosindulin derivative is then precipitated from its alkalinesolution by addition of hydrochloric acid.

Fifteen kilos of the polyoxy-rosindulin, obtained in the above-describedmanner, are dissolved with six kilos caustic-soda lye of 4:0 Baum infifty liters of water. A solution of forty kilos crystallized sodiumsulfid and fifteen kilos of sulfur in little water is now added. Themixture is then heated gradually in an oil-bath up to 160 centigrade andkept five hours at this temperature. The melt is then dissolved inwater, and the new sulfur dye is precipitated from the so-obtainedsolution by hydrochloric acid. It is filtered, washed, and dried.

The new product is insoluble in water. In an aqueous solution ofsodium-sulfid it is soluble with a bluish-red color, which is notaltered by addition of an alkali. In alcohol and in dilutecaustic-alkali lyes it is little soluble. In concentrated sulfuric acidit is soluble with blue color. It' dyes a red violet on unmordantedcotton in a bath containing sodium sulfid.

What I claim is 1. As a new process for the manufacture of a sulfur dyeby boiling benzene-azo-alphanaphthylamin in aqueous suspension withpara-amidophenol, and melting the polyoxyrosindulin obtained with analkali polysulfid.

2. As a new product the reddish-violet sul-.

THEODOR MUOHALL.

Witnesses:

IGNAT. ROSENBERG, JEAN GRUND.

